Membrane seawater desalination pressurization and energy recovery integrated method and device

Abstract

The invention relates to a membrane seawater desalination pressurization and energy recovery integrated method and a membrane seawater desalination pressurization and energy recovery integrated device. Piston rods of single-rod seawater cylinders are connected with single-rod oil cylinders to form two or more working combined bodies which operate alternately; the oil cylinders drive the seawater cylinders to move back and forth; one piston cavities of the seawater cylinders suck high pressure strong brine in the process of moving forward and drain the high pressure strong brine in the returning process; and the other piston cavities of the seawater cylinders suck raw seawater in the returning process, pressurize the raw seawater in the process of moving forward and continuously and stably output the pressurized high pressure raw seawater to a reverse osmosis membrane modulus.

Description

Technical field [0001] The invention relates to a high-pressure pump, an energy recovery device and a booster pump required for reverse osmosis membrane seawater desalination, in particular to a device that integrates a high-pressure pump, a booster pump and an energy recovery system. Background technique [0002] Desalination is a way to solve the global shortage of fresh water resources. There are two commonly used methods: thermal and membrane methods. Among them, membrane seawater desalination technology using reverse osmosis membranes has been widely used due to its low cost and low energy consumption, and has gradually become the mainstream. [0003] In the seawater desalination system, the pretreated seawater with lower salinity that enters the desalination system is raw seawater, which is pressurized to form high-pressure raw seawater, and part of it becomes low-pressure fresh water after passing through the reverse osmosis membrane group, and the rest becomes high-pressure...

AI Technical Summary

Problems solved by technology

The sum of the two costs accounts for about 1 / 3 of the total investment cost, the electricity consumption accounts for more than 2 / 3 of the total electricity consumption, and the electricity consumption cost accounts for more than 1 / 3 of the operating cost. The power consumption is 35kwh, and under the existing membrane technology level, the limit power consumption should be around 2.5kwh, and there is still 1 / 3 of energy-saving space

The other is based on the principle of pressure exchange, that is, in the cylindrical cylinder, through the flow distribution mechanism, the high-pressure concentrated brine directly transfers the pressure potential energy to the original seawater, the transfer efficiency is very high, and the energy recovery efficiency can reach more than 90%; according to The flow distribution methods are different, and can be further subdivided into the structure of valve flow distribution without piston on the end face of the rotating cylinder and the valve flow distribution structure with piston on the fixed cylinder; The structure is simple but there will be 25% blending, which requires an independent booster pump, which will reduce the overall efficiency; and the valve distribution structure with pistons in the fixed cylinder, no need to set up a booster pump, the efficiency can be higher, but its control Organization is more complex

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